Nicotinamide adenine dinucleotide (NAD) plays fundamental roles in both cellular energy metabolism and cellular signaling. In energy metabolism, the chemistry of the pyridine ring allows NAD to readily accept and donate electrons in hydride transfer reactions catalyzed by numerous dehydrogenases.
The preparation of a class of compounds, comprising several subclasses, which act as inhibitors of the formation of nicotinamide adenyl nucleotide, and their use thereof as anti-tumour agents, is already described in the patent applications WO00/50399, WO97/48695, WO97/48696, WO97/48397, WO99/31063, WO99/31060, WO99/31087, WO99/31064, WO00/50399, and WO03/80054.
One of these inhibitors, (E)-N-[4-(1-benzoylpiperidin-4-yl)butyl]-3-(pyridine-3-yl)-acrylamide also known as APO866, FK866, WK175, or WK22.175 and hereinafter referred to as FK866 [International Non-proprietary Name], is especially described in the literature as an anticancer agent. FK866 may be used for treatment of diseases implicating deregulated apoptosis such as cancer. It has been demonstrated in the prior art that FK866 interferes with nicotinamide adenyl dinucleotide (also known and hereinafter referred to as NAD) biosynthesis and induces apoptotic cell death without any DNA damaging effects.
Additionally, FK866 ((E)-N-[4-(1-benzoylpiperidin-4-yl)butyl]-3-(pyridin-3-yl)acrylamide) induces apoptosis in HepG2 cells without having primary effects on cellular energy metabolism. (Hasmann M, Schemainda I. FK866, a Highly Specific Noncompetitive Inhibitor of Nicotinamide Phosphoribosyltransferase, Represents a Novel Mechanism for Induction of Tumor Cell Apoptosis. Cancer Res 2003; 63:7436-7442. [PubMed: 14612543]) Instead of causing immediate cytotoxicity, it inhibits NAMPT and depletes the cells of NAD, suggesting that FK866 could be a promising agent against cancer cells that rely on nicotinamide to synthesize NAD. The crystal structure of the NAMPT-FK866 complex reveals that the compound binds at the nicotinamide-binding site of NAMPT to inhibit its activity. FK866 has been tested in a murine renal cell carcinoma model and shown to display anti-tumor, antimetastatic, and anti-angiogenic activities (Drevs J, et al. Antiangiogenic potency of FK866/K22.175, a new inhibitor of intracellular NAD biosynthesis, in murine renal cell carcinoma. Anticancer Res 2003; 23:4853-4858. [PubMed:14981935]).
In a mouse mammary carcinoma model, FK866 also induces a delay in tumor growth and an enhancement in tumor radiosensitivity accompanied with dose-dependent decreases in NAD levels, pH, and energy status. A chemosensitizing effect of FK866 has also been observed on anti-neoplastic 1-methyl-3-nitro-1-nitrosoguanidinium (MNNG)-induced cell death in THP-1 and K562 leukemia cell lines (Pogrebniak A, et al. Chemopotentiating effects of a novel NAD biosynthesis inhibitor, FK866, in combination with antineoplastic agents. Eur J Med Res 2006; 11:313-321. [PubMed: 17052966]).
The efficacy of GMX1777 was evaluated in xenograft models and the pharmacokinetic profile of GMX1778 and its effect on nicotinamide adenine dinucleotide cellular levels was measured by liquid chromatography/mass spectrometry. (Beauparlant P., et al. Preclinical development of the nicotinamide phosphoribosyl transferase inhibitor prodrug GMX1777. Anticancer Drugs. 2009 June; 20(5):346-54).
GMX1777 is a water-soluble intravenously administered prodrug of GMX1778 that Gemin X in-licensed from LEO Pharma (LEO numbers: EB1627 and CHS828, respectively). These compounds and other substituted cyanoguanidines have the structures of Table 1.
TABLE 1A B1 B2 CSubstituted Cyanoguanidines with Defined Pharmacological Effects:A Cytotoxic CHS 828;B Potassium channel openers pinacidil (B1) and 12 g of compound as described in Perez-Medrano et al (B2); andC Histamine-II receptor antagonist cimetidine. (from Lövborg et al. BMC Research Notes 2009 2:114 doi:10.1186/1756-0500-2-114)
More recently, CHS-828 has been identified as a NAMPT inhibitor (Olesen U H, et al. Anticancer agent CHS-828 inhibits cellular synthesis of NAD. Biochem Biophys Res Commun 2008; 367:799-804. [PubMed: 18201551]). CHS-828 has been shown that this compound potently inhibits cell growth in a broad range of tumor cell lines, although the detailed mechanism for this inhibitory effect of CHS-828 remains undetermined (Ravaud A, et al. Phase I study and guanidine kinetics of CHS-828, a guanidine-containing compound, administered orally as a single dose every 3 weeks in solid tumours: an ECSG/EORTC study. Eur J Cancer 2005; 41:702-707. [PubMed: 15763645]). Both FK866 and CHS-828 are currently in clinical trials for cancer treatments.
There are numerous uses for drugs which inhibit NAMPT.
Lack of NAMPT expression strongly affects development of both T and B lymphocytes. By using mutant forms of this protein and a well-characterized pharmacological inhibitor (FK866), authors demonstrated that the ability of the NAMPT to regulate cell viability during genotoxic stress requires its enzymatic activity. Collectively, these data demonstrate that NAMPT participates in cellular resistance to genotoxic/oxidative stress, and it may confer to cells of the immune system the ability to survive during stressful situations such as inflammation. (Rongvaux, A., et al. The Journal of Immunology, 2008, 181: 4685-4695).
NAMPT may also have effects on endothelium (EC) in relation to high glucose levels, oxidative stress and on aging. It is also believed that NAMPT may enable proliferating human EC to resist the oxidative stress of aging and of high glucose, and to productively use excess glucose to support replicative longevity and angiogenic activity.